AUGUSTA, Maine — The Maine Republican Party is alleging that Angus King’s first television advertisement in the campaign for Maine’s open U.S. Senate seat violates a provision in federal election law requiring candidates to state orally and in writing that they approve their TV spots.

In a two-page complaint the party filed with the Federal Election Commission, Maine Republican Party Chairman Charlie Webster notes that the federal “stand by your ad” provision requires candidate television ads to carry both oral and written statements from the candidate that he or she approves the content of their advertising.

An FEC spokesman confirmed Wednesday that the commission had received the complaint.

King’s ad, which he launched Friday, features the former governor saying, “I’m Angus King, and I approve this message,” but carries no approval message in writing. An ad launched earlier last week by Republican Charlie Summers carries both verbal and written statements stating Summers approves his television spot.

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“Angus King should promptly take down this ad, correct it, and apologize to the people of Maine for neglecting the very laws he says are so important for clean and fair elections,” Maine GOP spokesman David Sorensen said in a statement.

King spokeswoman Crystal Canney said in a statement that the GOP complaint is part of a pattern in which “political partisans make things up and send out a press release.”

“We believe we have complied with the spirit of the law. If Charlie Webster is confused, we can’t help that,” Canney said. “Our legal team has looked and we believe we have complied.”

The campaign plans to change future ads to adhere more closely to the “stand by your ad” provision, she said. An ad the campaign begins airing Thursday, called “Godzilla and the Real Angus,” carries the written disclaimer “Paid for and authorized by Angus King for U.S. Senate campaign.”

Canney also noted that the Maine GOP had used images from the King ad and posted them on YouTube as a rebuttal video after questioning in a press release the King campaign’s right to use Google Earth images in its ad. The King campaign produced the contract proving it had permission to use the Google images, and the GOP rebuttal video is no longer viewable on YouTube due to a copyright claim.

The “stand by your ad” provision came into effect as part of the 2002 McCain-Feingold campaign finance law that aimed to more closely regulate campaign financing and spending.

FEC complaints and allegations of election law violations are a common tactic political campaigns use against their opponents. In August, for example, Hawaii Senate candidate Mazie Hirono said her Republican rival, Linda Lingle, violated the “stand by your ad” provision in an ad.

With Webster’s complaint, an FEC lawyer will first review it to determine if it falls within the commission’s jurisdiction, then allow the King campaign 15 days to respond, according to complaint filing guidelines on the FEC’s website. If the FEC finds a campaign violated election law, the campaign could be subject to fines or the commission could use its alternative dispute resolution process.

If the FEC takes up the complaint, the matter is unlikely to be settled before this fall’s Nov. 6 election. In fiscal year 2011, the FEC says it handled 145 enforcement cases in an average of 10 months. Those cases led to a total of $527,000 in civil penalties.

On Wednesday, Politico cited the Maine Senate race among three that “lurk as potential sleepers” where an upset is possible “because of slip-ups or better-than-expected performances by candidates.” The other races are in Connecticut and Indiana.

As for Maine, Politico said: “Judging by sheer polling, Maine ranks pretty far down the list of states where Republicans might pull an upset. By all appearances, the race is former Gov. Angus King’s to lose.”